|Identification of a gene involved in plasmid structural instability in
Appl. Microbiol. Biotechnol. 97: 8219-8226. 2013.
Y. Kitade, S. Okino, W. Gunji, K. Hiraga, M. Suda, N. Suzuki, M. Inui and H. Yukawa.
|Expression plasmids that facilitate production of bio-based products are
susceptible to toxic effects that frequently affect plasmid structural
stability in recombinant microbial cells. In order to enhance plasmid stability
in recombinant Corynebacterium glutamicum, an expression plasmid containing genes of the Clostridium acetobutylicum butyryl-CoA synthesis operon with high structural instability within wild-type C. glutamicum was employed. From a total of 133 mutants exhibiting disruptions in 265
suspect genes, only cgR_0322-deficient mutant was able to maintain the expression plasmid intact. The
mutant exhibited normal growth under standard laboratory conditions but
its transformation efficiency was about one order of magnitude lower than
that of wild-type strain. The cgR_0322 gene encodes an endonuclease that is active against single- as well as double-stranded DNA substrates in the presence of Mg(2+). The cgR_0322-deficient strain should therefore facilitate the development of more robust
C. glutamicum strains to be used as microbial production hosts.